ring-multipart-nodeps

A zero-dependency replacement for ring.middleware.multipart-params with Babashka compatibility.

Overview

ring-multipart-nodeps parses multipart/form-data requests in Clojure without external dependencies. It provides the same functionality as Ring's built-in multipart-params middleware but works in Babashka environments.

Features

• Drop-in replacement for ring.middleware.multipart-params
• Zero external dependencies
• Works in both JVM Clojure and Babashka
• Proper handling of binary files (PNG, JPG, PDF, etc.)
• Supports custom file stores (in-memory or temp files)
• Progress tracking for file uploads

Installation

Usage

The API mirrors Ring's standard multipart handling:

(ns my-app.handler
  (:require [ring-multipart-nodeps.core :as mp]))

;; Basic usage
(def app
  (-> handler
      (mp/wrap-multipart-params)))

;; With custom options
(def app-with-options
  (-> handler
      (mp/wrap-multipart-params
        {:store (mp/temp-file-store)  ;; or mp/byte-array-store for in-memory
         :encoding "UTF-8"
         :fallback-encoding "UTF-8"
         :progress-fn (fn [request bytes-read content-length item-count]
                        (println "Processed" bytes-read "of" content-length "bytes"))})))

Supported Options

Option	Description
:encoding	Forced character encoding for fields. Overrides part Content-Type.
:fallback-encoding	Encoding used if part has no Content-Type charset. Defaults to request encoding or UTF-8.
:store	Function to handle file uploads. Takes map with :filename, :content-type, :stream, :part-headers. Default is temp-file-store.
:progress-fn	Function called during uploads with parameters: request, bytes-read, content-length, item-count.

Not Yet Supported

The following options from Ring's original middleware are not yet supported:

• :max-file-size - Limit on maximum file size in bytes
• :max-file-count - Limit on maximum number of files in a request
• :error-handler - Custom handler for when limits are exceeded
• Special handling of a part named _charset_ for encoding detection

License

Copyright © 2025 Frozenlock

Distributed under the Eclipse Public License version 2.0.